1. Field of the Invention
The invention relates to a process for the electrophoretic deposition of metal powders capable of producing thick deposits suitable for recoating parts, particularly nickel-based superalloy parts intended for aeronautical applications or turbomachines, using diffusion brazing techniques. The invention relates also to the composition of the electrophoresis bath which is used in the process and from which the metal powders are deposited.
2. Summary of the Prior Art
It is known to carry out, both in repair work and in the manufacture of new parts, recoating of parts using diffusion brazing techniques, the coating material taking a variety of forms but particularly a mixture of metal powders which, for example, may be put in place in paste form by injection using a syringe. Examples of these techniques are described in EP-A-75497 and EP-A-165104.
It is also known from GB-A-1466204 to provide an anti-corrosion coating on a superalloy part by electrophoretic deposition of a mixture of aluminium powder and a powder of a chromium-aluminium alloy from a suspension of these powders in an organic dielectric based on isopropyl alcohol, nitromethane and zein, and a diffusion heat treatment.
FR-A-2308704 further describes a process for coating a metal surface by electrophoresis using an aqueous dispersion of aluminium powder and a theromsetting acrylic resin.